Anything and absolutely everything can be used by criminals. Remember Bitcoin is just a tool that they can use to do some bad things but it also has good purposes so it all depends on the people who are using it, it is their decision whether to use it for a good cause or a bad thing. It doesn't make Bitcoin bad, do not fall on the black propaganda for people to think that Bitcoin is bad. In fact all the things in this world even fiat and your love for your family can be used against us right? does that mean to have money or to love is bad? I don't think so.